Lifting mechanism for industrial trucks



April 13, 1948. H. J. FRAMHEIN 2,439,599

-LIFTING um'cmm'xsu For: mnuswnm. wicks.

Filed April 1943" 3 Sheefcs -Sheet 1 INVENTOR BY M14,

ATTORNEY .AP 1 1943- H. J. FRAMHEIN LIFTING MECHANISM FOR INDUSTRIAL TRUCKS 3 Sheets-Sheet 2 Filed April 6, 1945 mm Q Q INVENTOR .ffi-d iem I ATTORNEY April 13; 1948. H. J. FRAMHEIN 2,439,599

LIFTI'NG MECHANISM FOR INDUSTRIAL TRUCKS Filed April 6, 1943 3 Sheets-{Sheet 3 ATTORNEY Patented Apr. 13, 1948 LIFTING .MECHANISM FOR INDUSTRIAL TRUCKS Herbert J. Frarnhein, Chicago, 111., assignor to The Yale & Towne Manufacturing Company, Stamford, Conn, a ccrpcrationof Connecticut Application April 6, 1943, Serial No. 481,957

This invention relates to a truck of the type my earlier application the rear lifting Wheels of I theelevating platform are'adapted to be moved throughcams mounted on the lifting head and actuated incidental to the lifting of the forward end of the elevating platform as that forward endmoves upwardly relatively to the lifting head.

I have conceived it highly desirable that the lifting cams be mounted on the elevating platform provided this can be done advantageously. and in such a manner that the said cams maybe readily actuated as the forward end of the elevating platform is moved upwardlyrelatively to the lifting head. TOObtQlIlISUCh means'is extremely difiicult in a truck of theclass having a lifting head and an elevating platform, and the'conception of such means and their reduction to practice "has been a considerable problem.

Afeature of this'invention resides in the means whereby the lifting cams are "mounted on the elevating platform for actuation by meanson the lifting head as the cams moveupwardlywith' the elevating platform. A further feature resides in the arrangement of "the parts whereby they do not interfere with the under clearance of the truck.

More particularly; it is a featureof my invention that the lifting cams are adapted for mounting on an elevating platform "that is moved verticallyrelatively toalifting head, and with the said-elevating platform =being assembled on i the lifting head and maintained againstpivotal movement relatively thereto at all times. "As a more detailed feature of the invent-ionthe elevating platform on which the cams are mounted is adapted for vertical movement through rollers and channels'that serve to -mountthe elevating platform for vertical sliding movement while maintaining the platform against pivotal movement on thelifting head.

Actually, "it is the conception or suitable means for themountingof the lifting cams-for pivotal movement relatively to the elevating platform 12. Claims. ((113254-2) and in a position to be moved pivotall-y relatively to the platform by 'meanson' the lifting head; that forms the main basis of the invention of this application. 7

I have thus described generally my invention in order that its relation to the prior artand the contribution thereofto the priorart may be betterappreciated. Fora description of the invention-and of a preferred mechanical form thereof, I sh'all refer to the accompanyingdrawlugs and the description that follows. Those skilled in the art will of course appreciate that once thebasis of my contribution to the'art is disclosed to those skilled inthe art, it will be possible for those skilled in the art to develop mechanisms different from that Ishall hereindescribe but yet effective to contribute the operations -andresults contributed by my invention.

It is important therefore that my patent claims should not be limited to the specific disclosure I shall herein show and describe.

"Referring now to the drawings Fig. 1- is an elevation andpartial section of-a truck embodying my'invention.

Fig. 2 is a view looking downwardly on the rear end of the truck of Fig. 1.

Fig. 3 isanen'larged elevation and partial section of part of Fig, 1,

Fig; 4-is asection taken vertically just outside the plane of the vertical ram of my-truck and showing'the parts of Fig. *3 when the elevating platform is lifted relatively to the lifting head. 7 Fig; 5 is an exploded view showing the rear end of the lifting head and the forward end of the elevating platform.

Referringnow more particularly to the drawings, and especially Figs. 1 and 5, the lifting head of my truck is designated generally by reference numeral 19. "The forward end'of' this lifting head is supported by driving wheels I! forming part of a steering head 12 on which is mounted a traction unit l3 adapted to drive the wheels II. A controlling and steering lever for the steering head of the truck is designated by reference numeral M and is pivoted at l5 to the steering head 12, This construction is fully illustrated and described in my patent application Ser. No.*390,931, filed-April 29, 1941, now Patent No, 2,327,583, dated August 24, 1943, for a Motorized lift truck, and need not be described in any more detail here. -I t is obvious of course that my invention need not necessarily "be used in a motorized truck, such a truck being-shown here merely as illustrative of one form of truck.

The rear end "of the *liftinghead; as shown best in Fig. 5, has a pair of vertical uprights 16 formed with channels ll. The upper ends of the uprights l5 are braced by a crossbar [8 that is assembled to the uprights through the intermediary of angle bars l9. At this point it may be well to indicate that the present practice in the lift truck art is to fabricate parts as illustrated by me in the drawings, but those skilled in the art will rappreciate that the parts may be fabricated in other ways as manufacturing processes change and develop.

For imparting lifting movement to the elevating platform to be described presently, my lifting head carries a hydraulic lifting ram assembly 20. This hydraulic assembly, as is best seen in Figs. 4 and 5 is equipped with a lower ear 2| mounted on a pin 22, the pin 22 being carried in suitable bores 23 of bearing blocks 24 that are welded or otherwise secured to a plate 25. The plate 25 is secured to the lower ends of the uprights l5 and to side plates 25 of the lifting head II] to form an integral part of the lifting head.

The hydraulic ram assembly 20' carries a ram plunger 21, the upper end of which is formed with an ear 28 whereby through a stub shaft 29 it may be pivotally secured to a pair of brackets 30, best shown in Fig. 5 as welded or otherwise secured to the vertical standard 3| of the elevating platform 32. It is obvious, of course, that vertical movement of the ram plunger 2? will effect the upward movement of the vertical standard 3| of the elevating platform .32.

The elevating platform 32 has mounted on its vertical standard 3! a pair of vertical plates 33. Each of these vertical plates carries a pair of rollers 34 in the standard manner known in the art. These rollers 34 are formed to fit within the channels I! of the vertical uprights [5 of the lifting-head so as to guide the elevating platform 32 for vertical movement relatively to the uprights It. It is obvious also, that the rollers 34 lying in the channels I? as shown best in Fig. 2, maintain the elevating platform assembled to the lifting head and against pivotal movement relatively thereto.

The elevating platform 32 is formed in the shape of a U in common with a known practice in the industrial lift truck art. The legs of this U are of course alike except that they are in opposite relation as is well illustrated in Fig. 2. I shall now describe the construction of one leg of the U platform and the means whereby lifting means carried thereby is actuated by devices mounted on one side of the lifting head.

Referring to Figs. 1, 2 and 5, the leg 45 of the elevating platform 32 is shown as having an upper plate 4| formed with an opening at 42 to expose a rear wheel lifting link 53. The link 43 is pivoted through the shaft 44 to bearing lugs 45 forming a part of the leg 59. Lugs 45 on the link bear against surfaces 4! on the leg 45 to limit rotation in one direction of the link 43 relatively to the leg. A lifting wheel 43 is mounted on an axle 49 carried by the link 45 so as to rotate on the said axle, and so as to move with the link to lift the rear end of the elevating platform. For so movin the lifting link 43, I rely on a rod assembly 59 that is pivoted at its rear end to the lifting link 43 about a pin 5!. It is obvious now that movement to the left of the rod assembly 50 in Figs. 1 and 2 will effect lifting movement of the rear wheel lifting link 43. The constructionof the U leg and the parts just described is old in the art and per se is not my invention. My invention includes means for moving the rod asmovement of the rear wheel lifting links 43, as will of course be apparent to those skilled in the art.

At its forward end, each rod assembly '59 is pivoted through a stub shaft 53 to a lifting cam 54. I shall describe but one of these cams and its actuating means, The lifting cam 54, as best seen in Fig. 5, is pivoted about a shaft 55 that extends between a pair of parallel brackets 56, the shaft 55 being suitably carried by the brackets. The brackets '56 are secured as by welding or by bolting, as the case may be, to the vertical standard 3| of the elevating platform 32. In the preferred form of my invention the pair of brackets 55 are integral parts of a U shape bracket assembly having a rear plate 51 as is quite apparent from Fig. 5. Because of this mounting of the cam 54, it is movable bodily with the elevating platform while rotatable on its pivot relatively thereto.

The cam 54 is formed with a cam surface 58 adapted to cooperate with a roller 59 extending outwardly from the plate 25 of the lifting head. The roller 59 may be mounted on the plate26 in any preferred manner and extends through a slot 50 in the bracket 56 adjacent thereto so as to occupy a position overlying cam 54 and with its periphery against the cam surface '58 of the cam 54. There are of course two rollers 59, one at each side of the lifting head.

Referring now to Fig. 3, we find the parts there in the position in which they lie when the elevating platform 32 of the truck is in its fully lowered position. It will be noted therefore that the particular roller 59 shown is near the upper end of the slot 60 of the particular bracket 55 illus-.

trated, We note also that the right hand end of the cam surface 58 is under the roller 59 in a position to rotate the cam 54. The lifting wheels 48 at the rear end of the platform are of course in the lowered position illustrated in Fig. 1, the cam 54 in that figure lying in the same position as in Fig. 3.

If now the hydraulic lifting ram assembly 20 is actuated, the ram plunger 21 will move vertically and will through the shaft 29 move the elevating platform 32 and its standard 3| into the position of Fig. 4. The position of Fig. 4 is the elevated position of the elevating platform as will be apparent. During this upward movement of the elevating platform the roller 59 has been held against vertical movement and therefore occupies now a position near the lower end of the slot 60 in the particular bracket 56 that is illustrated. The cam 54, having moved upwardly from the position of Fig. 3 to the position of Fig. 4 through its pivotal mounting on shaft 55 of the brackets 56, has been rotated by the roller 59, thisrotation taking place about the shaft 55. During this rotary movement, the cam 54 of course, through the pin 53 imparted a considerable movement to the left to the rod assembly 59. This movement of the rod assembly 5|] has effected the lifting movement of the particular lifting link 43 and wheel 48 actuated by the particular rod assembly 50 illustrated.

Therefore while the elevating platform 32 was being lifted at its forward end, the rear end of the platform was also being lifted through theintermediary of the pair of cams 54, the rod assemblies 59, and the lifting Wheels 48.

I believe that the operation and construction of my invention will now be quite apparent to those skilled in the art.

easement I: 1 In a truck or the rclass described" a -:lifting head liavinga vertical standardan :elevatingiplatform having a forward vertical standard, rollers on saidplatform standardrmoving. m channels on said lifting :head standard; lifting wheels at' the rearend of said elevating. platformg-meansmount mg said llfting'wheels for lifting movement relatlvely to said elevatingplatform, lifting-means for :lifting the forward standard of --said elevat= ing'aplajtform relatively to-s'aid' lifting head; lifting cams piv'oted on s'aid elevating platform, means of connection between-said liftingeams and said lifting whack-mounting means whereby pivotal movement of said lifting cams effects-movement of sald-lifting -wheels in a liftingfdirectionxand meanswfi'xed on said lifting head #andvbearing against-said lifting'cams to pivot said lifting cams as i said cams move i with. said elevating 'platform relatively to said lifting head.

2. In :a truckof the class described, a lifting head, anelevating platform, means mounting said platform for vertical movement relatively tosaid lifting head and holding said platfomn against pivotal movement relatively to said lifting head,

lifting wheels at the rear end" of:sald': elevating platform, means "mounting said lifting Wheels for lifting movement relatively to said elevating plab form, lifting means for lifting the forward "end of said:elevatingplatform relatively to said lifting headplifting cams pivoted on said'elevatlng platform, '=means *of' conneotion between said liftingcams and 'said lifting wheel m'ounting means wherebypivotal: movement of said lifting earns effects movernent of said' wheel's in a liftingadireor deman means fixed on "said iiftmg nead and bearing-against said lifting cams to'pi-vot's'aid lifting F canis as said cams move with said elevatin platform relatively to s'aid lifting nead.

3. In'a truck ofthe clas's describeda lifting head having a -vertical standardan elevating platfoini having a forward vertic andard, rollers on sai'd platform standard movmg' irichafm'els on 'said li ftiiig head standard," lifting wheels at therear endof-said elevating platform,mans mounting said lifting wheels for lifting movement relatively to saidelevating platform, lifting means for lifting the forward standard of said elevating platform relatively to 'saidlifting head, lifting cams pivoted on said elevating platform and movable bodily with said elevating platform, means of connection between Said lifting cams and said lifting wheel mountirigmeans whereby pivotal movement of said lifting cams effects movement of said lifting wheels in a lifting "direction, and-rollers mounted on shafts fixed to said lifting head and bearing against saidlifting cams to pivot said lifting cams as said cams move with said elevating platform relatively to said lifting head.

4. In a truck of the class described, a lifting head having a vertical standard, an elevating platform having a forward vertical standard, means mounting said platform standard for vertical movement relatively to said lifting head standard while maintaining said standards in spaced relation, lifting wheels at the rear end of said elevating platform, means mounting said lifting wheels for lifting movement relatively to said elevating platform, lifting means for lifting the forward standard of said elevating platform relatively to said lifting head, lifting cams pivoted on said elevating platform, means of connection between said lifting cams and said lifting wheel mounting means whereby pivotal movemerit omsaid liftingpams :efiects movement .of said wheels in a lifting direction, and rollers mounted orrshafts. fixedl to. said lifting head and bearing iragainsti said: lifting cams to pivot said lifting-foams "as said camsmove with saidelevating; platform" relatively to said lifting head.

5. In aitr'uc'kof the class described, a lifting head iihavingi a vertical -standard, an elevating platform "having a forward vertical Q'standard, rnll'e'rs on saidrplatform standard movingmin channels on 'said lifting head standard, lifting wli'e'els a't the: rear end of said elevating platform, means amounting "said lifting wheels for liftiiig'movementrelatively to s'aid'elevatingip'latform, lifting means for lifting the forward end of sai delevating platform relatively to "said 11a:

ing had a -pair of brackets projecting from said eievatmg platrorm at each" side thereof a lifting earn p voted betweenthe -br'ackets of :each of said pair of brackets' on a :sha'ft extending between said brackets,- means of connection between said lifting cams and said lifting wheel mountin means --whereby "pivotal movement I of said lifting fidts movement bf said llftil lg Wheels in a lif ng direction, and rollers mounted on shafts-fixed*to said lifting "head and bearing against said lifting cams-topivot said liftingcams as said cams move with a said elevatin platform relatively to said liftinghead.

6. In a truck "of theclass describeda lifting liea'd,- ah elevating platform, means mounting said platf-orrnfor lifting movement relatively-to sa'id lifting head, lifting wheels at the rear end of said =-elevating platform, means mounting-said lifting wheels for lifting movement relatively to said elevating platform, lifting means for lifting theforward endofsaid elevating platform relatively to'said lifting head, a pair of brackets projetting from said elevating platforinat each side thereof a lifting-j cam pivoted between each of saidTpair" of brackets on" a "shaft extending between said brackets, means of "connection between said lifting cams and said lifting'wheel mounting means whereby pivotal movement of saidnftin eams ffectsmovement'of said wheels in a lifting direction, and rollers mounted "on shafts axes to said lifting head and bearing against'saidlifting cams to pivot saidTli'ftinfg cams as said cams move with said elevating platform ilatlvlyto said lifting head. I

"'LIn a' truck ofltheclass described, a lifting head having a vei tical standard, an elevating platform' having a forward vertical standard,

- rollers onsaid platform standard m'ovingin channels onsaid'li'fting. head standard, lifting wheels at the rear endof said elevating.platform,. means mounting said lifting wheels for lifting movement relatively to said elevating platform, liftin means for lifting the forward end of said elevating platform relatively to said lifting head, a

, pair of brackets projecting from said elevating platform at each side thereof, a lifting cam pivoted between the brackets of each of said pair of brackets on a shaft extending between said brackets, means of connection between said lifting cams and said lifting wheel mounting means whereby pivotal movement of said lifting cams effects movement of said lifting wheels in a lifting direction, and a roller mounted on a stub shaft at each side of said lifting head and extending through an opening in a bracket of each to pivot said lifting cams on their shafts as said cams move .with said elevating platform relatively to said lifting head.

8. In a truck of the class described, a lifting head, an elevating platform, means'mounting said elevating platform for lifting movement relatively to said lifting head, lifting wheels at the rear end of said elevating platform, means mounting said lifting Wheels for lifting movement relatively to said elevating platform, lifting means for lifting the forward end of said elevating platform relatively to said lifting head, a pair of brackets projecting from said elevating platform at each side thereof, a lifting cam pivoted between each of said pair of brackets on a shaft extending between said brackets, means of connection between said lifting cams and said lifting wheel mounting means whereby pivotal movement of said lifting cams effects movement of said wheels in a lifting direction, and a roller mounted on a stub shaft at each side of said lifting head and extending through an opening in a bracket of each of said pair of brackets so as to overlie the cams pivoted between said brackets, said rollers acting to pivot said lifting cams on their shafts as said cams move with said elevating platform relatively to said lifting head.

9. In a truck of the class described, a lifting head having a vertical standard, an elevating platform having a forward vertical standard, rollers on said platform standard moving in channels on said lifting head standard, lifting links pivoted to the rear end of said platform, lifting wheels movable with said links to lift the rear end of the platform, lifting means for lifting the forward standard of said elevating platform relatively to said lifting h'ead, lifting cams pivoted on said elevating platform, rods connecting said cams to said lifting links whereby pivotal movement of said lifting cams effects lifting movement of said lifting links, and lifting wheels, and rollers mounted on shafts fixed to said lifting head and bearing against said lifting cams to pivot said lifting cams as said cams move with said elevating platform relatively to said lifting head.

10. In a truck of the class described, a liftin head, an elevating platform mounted for elevating movement relatively to said lifting head, a pair of spaced brackets at each side of the forward end of said elevating platform, a pivot shaft extending between the spaced brackets of each pair of brackets, a cam pivoted on each of said shafts and having a curved liftin surface integral therewith, a rod pivoted to each of said cams and extending toward the rear end of said platform, lifting wheels at the rear end of said elevating platform connected to said rods for movement by said rods, lifting mechanism for lifting said elevating platform relatively to said lifting head, and means fixed to said lifting head extending through openings in certain of said brackets for contact by the lifting surfaces of said cams as said cams move with said elevating platform wherebysaid cams are rotated on their pivots to actuate said rods and lifting wheels.

11. In a truck of the class described, a lifting head, an elevating platform mounted for elevating movement relatively to said lifting head, a pair of spaced brackets at each side of the forward end of said elevating platform, a pivot shaft extending between the spaced brackets of each pair of brackets, a cam pivoted on each of said shafts, a rod pivoted to each of said cams and extending toward the rear end of said platform, lifting wheels at the rear end of said elevating platform connected to said rods for movement by said rods, lifting mechanism for lifting said elevating platform relatively to said lifting head, and rollers mounted on shafts fixed relatively to'said lifting head and contacted by said cams as said cams move with said elevating platform whereby" said cams are rotated on their pivots to actuate said rods and lifting wheels.

12. In a truck of the class described, a lifting head, an elevating platform mounted for elevating movement relatively to said lifting head, a pair of spaced brackets ateach side of the forward end of said elevatin platform, a pivot'shaft extending between the'spaced brackets of'each pair of brackets, a cam pivoted on each of said shafts,a rodpivoted to each of said cams and extending toward the rear end of said platform, liftingwheels at the rear end of said elevating platform connected to said rods for movement by said rods, lifting mechanism for lifting said elevating platform relatively to said lifting head, and rollers mounted on shafts fixed relatively to said lifting head and contacted by said cams as said cams move with said elevating platform whereby said cams are rotated on their pivots to actuate said rods and lifting wheels, said rollers protruding-through openings in a bracket of each pair of brackets into a position overlying said cams.

HERBERT FRAMHEIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Barrett Sept. 26, 1944 Schreck Oct. 3, 1944 Hennessy Nov, 16, 1920 

